Knock out models to dissect chemokine receptor function in vivo.

Chemokines are a family of small proteins involved in numerous biological processes ranging from hematopoiesis, angiogenesis and lymphocyte trafficking to the extravasation and tissue infiltration of leukocytes in response to inflammatory agents, tissue damage and bacterial or viral infection. Chemokines exert their effects by binding to specific G-protein-coupled seven-transmembrane receptors. In vitro studies suggest that the chemokine system is highly redundant in that most chemokines bind to more than one receptor and most receptors bind multiple chemokines. Therefore, targeted deletion of chemokine receptors has proved to be a useful tool for determining the distinct biological role of these molecules in vivo.